Escapement arming switch



Jan. 3, 1961 L. ALPERT ESCAPEMENT ARMING SWITCH 2 Sheets-Sheet 1 Filed Aug. 4, 1953 ll l2 m Ilnw Y N ANA") IOO ' L. ALPERT ESCAPEMENT ARMING SWITCH Jan. 3, 1961 Filed Aug. 4, 1953 2 Sheets-Sheet 2 United States Patent M ESCAPEMENT ARMING swrrcn Louis Alpert, China Lake, Calif assignor to the United States of America as represented by the Secretary of the Navy 1 Filed Aug. 4, 1953, Ser. No. 372,409 2 Claims. 01. zoo-61.45

(Granted under Title 35, US. Code (1952), sec. 266) The invention described herein may be manufactured and used by or for the Government of the United States of America for governmental purposes without the payment of any royalties thereon or therefor.

This invention relates to improvements in acceleration actuated electrical switches.

One of the objects of the invention is to provide an electrical switch for use in a missile, such as a rocket, forming a part of an arming circuit, adapted to be actuated after the missile has moved a substantially predetermined distance from its launching locus irrespective of variations in magnitude of the acceleration of the missile.

Another object is to provide a switch of the foregoing type which may be actuated by readily available acceleration responsive mechanism.

Still further objects, advantages, and salient features will become more apparent from the description to follow, the appended claims, and the accompanying drawing, in which:

Fig. 1 is a plan view of an arming'mechanism and an electrical switch incorporated therewith,

Fig. 2 is a section taken on line 2--2, Fig. 1,

Fig. 2A is the same section as Fig. 2 with parts disposed in other positions,

Fig. 3 is an enlarged section taken on line 33, Fig. 1,

Fig. 3A is the same section as Fig. 3 with parts disposed in other positions,

Fig. 4 is a section taken on line 44, Fig. 3,

Fig. 5 is a section taken on line 5-5, Fig. 3A,

Fig. 6 is an enlarged section taken on line 6-6, Fig. 1 (and a section taken on line 6-6, Fig. 7), and

Fig. 7 is a side elevation of Fig. 6 as viewed in the direction of arrow 7, Fig. 6, portions being broken away.

Referring in detail to the drawing the acceleration responsive mechanism 20 is illustrated as of the type disclosed in the patent application of Winfred F. Sapp for Rocket Fuse, Serial No. 342,039, filed March 12, 1953, now Patent Number 2,948,219. In general, this mechanism comprises an unbalanced rotor R, supported by a shaft 61 aifixed to the rotor for rotation therewith and journaled in an aperture 64 in a support 48a and normally locked against rotation by a set-back weight 88 which engages a roller 100 carried by pin 102. When weight 88 moves relatively rearward in response to forward acceleration of the device it disengages roller 100 permitting the rotor to rotate against the restraint of an escapement mechanism 50. Shaft 61 differs from the corresponding shaft of said application in that it is provided with an extension 161 which is half round in cross section.

Mechanism 20, just described in general, comprises a frame having a generally circular flat base 46 and a pair of spaced legs or supports 48, 48a extending perpendicular thereto at opposite edges thereof which form the supports for the mechanism and between which the rotor is journaled for rotation. Rotor R is circular in cross section and cut away at the sides thereof leaving chordal 2,967,217 Patented Jan. 3, 1961 portions 66 thus rendering it unbalanced. Weight 88 is slidably mounted for forward and rearward movement on a pair of pins 76, 78, secured to base 46 and is urged in a forward direction by springs 84, 86. The weight is U-shaped, having a pair of legs 92, 94 forming a space therebetween. Roller 160 is carried by the rotor and as shown in Fig. 2, is disposed within this space.

The escapement mechanism 50 indicated generally in Fig. 1 is shown in detail in Figs. 6 and 7. It is driven by the rotation of the rotor through a segmental internal gear 129 secured to one face of the rotor by a plurality of shouldered studs 131. The teeth of this gear engage the teeth of a pinion 130, the ends of which are journaled in side plates 52, 54, and has affixed thereto a larger gear 132. Gear 132 mashes with a pinion 134, similarly journaled, which has a similar large gear 136 aflixed thereto. Gear 136 mashes With a pinion 138 one end of which is journaled in side plate 54 and the other end in a lug 140, riveted to side plate 52, this pinion having an escapement wheel 142 affixed thereto, the teeth of which engage spaced pawls 144, 144a carried by a pallet 146, aflixed to a pintle 147, the ends of which are oscillatably carried by the side plates. A weight 143 threadedly engages stem 150 of the pallet, this weight being accessible for adjustment along the stem through aperture 152 in base 46 by means of a suitable tool, such as a screw driver, which may engage slot 154 in one end of the weight. In the operation of the escapement mechanism, torque applied by the rotor rotates the various gears of the gear train described and oscillates pallet 146 by the hammering engagement of its teeth on pawls 144, 144a which governs the speed of rotation of the rotor. Tests have revealed that the escapement mechanism accelerates during the first few strokes of the pendulum and runs continuously thereafter at a rate which is a function of missile acceleration to produce a substantially constant arming distance for a wide range of missile accelerations. To initiate operation of the escapement mechanism forward acceleration in the direction of arrow A of sufiicient magnitude to urge weight 88 rearwardly causes the weight to move from the position of Fig. 2, where the rotor is locked against rotation, to its rearward limit position shown in Fig. 2A. As soon as roller is disengaged from weight 83 the rotor rotates and finally reaches the position shown in Fig. 2A wherein it is locked against reverse rotation by a detcnt pin 114 (Fig. 7) which is spring urged into a suitable aperture in one side of the rotor (not shown). In event acceleration is not sustained to move the rotor to armed position the top surface of leg 94 of weight 88 will engage the roller and cam the rotor back to its original position under urge of springs 84, S6.

The electrical switch comprises a suitable support 10 connected by a frame F to support 48a and having a rectilinearly slidable member 11, urged toward shaft extension 161 by spring 12. A foot 13 on member 11 engages the outer end of extension 161 when the parts are in the position shown in Fig. 3, thus preventing movement of member 11. When shaft extension 161 rotates to the position shown in Fig. 3A, it releases member 11 for movement by spring 12, thus closing an electrical circuit 14 having a pair of contact points 15. The circuit may arm the missile in any manner well understood in the art. It will be apparent, also, that a circuit may be opened, instead of closed, by reorientation of the contact points and that the circuit may be employed for any purpose other than arming.

Obviously many modifications and variations of the present invention are possible in the light of the above teachings. It is therefore to be understood that within the scope of the appended claims the invention may be practiced otherwise than as specifically described.

What is claimed is.

1. In acceleration actuated mechanism of the type comprising an unbalanced rotor mounted for rotation in response to bodily acceleration of the mechanism adapted to rotate between an initial and final position, an escapement device operatively connected to the rotor adapted to be actuated thereby in response to rotation of the rotor and govern the speed thereof, a weight movable in response to bodily acceleration of the mechanism operatively associated with the rotor constructed and arranged to lock same against rotation in said initial position when the acceleration is below a predetermined magnitude and to unlock the rotor for rotation when the acceleration is above said predetermined magnitude and permit the rotor to rotate toward said final position, the improvements in combination comprising; a shaft operatively connected to the rotor and arranged for rotation by the 4 latter, a switch actuator engageable with an end of said shaft adapted to disengage said end upon predetermined rotation of said rotor, and an electric switch adapted to be actuated by the switch actuator.

2. Apparatus in accordance with claim l wherein the end of said shaft is non-circular in cross section, providing a cut-out, said actuator having a portion adapted to move into the cut-out when the actuator disengages said end.

References Cited in the file of this patent UNITED STATES PATENTS 

